"Evolutionism", is defined by the OED
as "[t]he theory
of evolution, evolutionary assumptions or principles".
Creationists tend to use the term evolutionism in order to suggest
that evolution and
creationism are
equal in a philosophical debate.

Development of usage

Anthropologists and biologists refer
to "evolutionists" in the 19th century as those who believed that
the cultures or life forms being studied are evolving to a
particular form (see Platonic
form). Very few scientists today, if any, believe that
evolution in culture or biology works that way, and serious
discussions generally take caution to distance themselves from that
perspective.

Evolutionary biology explains biotic changes in
terms of internal processes and gradual development as a natural
progression of previously existing lifeforms. Evolution neither
denies nor requires a role for divine
intervention. Before the 19th century there were a number of
hypotheses regarding the evolution of all material phenomena: suns,
moons, planets, earth, life, civilization, and society. The number
of hypotheses being propounded increased dramatically in the middle
of the 19th century.

Most scientists object to the terms evolutionism
and evolutionist because the -ism and -ist suffixes accentuate
belief rather than
scientific study. Conversely, creationists use those same
two terms partly because the terms accentuate belief, and partly
perhaps because they provide a way to package their opposition into
one group, seemingly atheist and materialist, designations which
are considered to be irrelevant to natural
science.